We address the issue of Ontology-Based Data Access, with ontologies represented in the framework of existential rules, also known as Datalog+/-. A well-known approach involves rewriting the query using ontological knowledge. We focus here on the basic rewriting technique which consists of rewriting the initial query into a union of conjunctive queries. First, we study a generic breadth-first rewriting algorithm, which takes as input any rewriting operator, and define properties of rewriting operators that ensure the correctness of the algorithm. Then, we focus on piece-unifiers, which provide a rewriting operator with the desired properties. Finally, we propose an implementation of this framework and report some experiments.
@article{arxiv.1311.3198,
title = {Sound, Complete and Minimal UCQ-Rewriting for Existential Rules},
author = {Mélanie König and Michel Leclère and Marie-Laure Mugnier and Michaël Thomazo},
journal= {arXiv preprint arXiv:1311.3198},
year = {2013}
}